Overclocking, Testing, and the Moving Multiplier

powertowerpro

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First, I would like to thank the tom's hardware overclocking community for taking the time to read and potentially respond to this post.

I have spent a good deal of time trying to research this issue before posting the question here. I wanted to cover my bases, but I never could find a satisfactory answer or solution, though there were some posts with questions.

I have average experience when it comes to building and overclocking computers, this is my 3rd build, but the first with Vista and the Q6600.

So before I get into it here is my build:


- Intel Core 2 Quad Q6600 Kentsfield 2.4GHz LGA 775 Quad-Core Processor Model BX80562Q6600
- ASUS P5KPL-AM/PS LGA 775 Intel G31 Micro ATX Intel Motherboard (cheap, I know)
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131350

- FSP Group Blue Storm II 500W ATX 2.2 SLI Ready Active PFC Power Supply
- Kingston HyperX 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Desktop Memory
- Vista 64 Ultimate SP1

So the basic principles of overclocking are relatively simple: Overclock in the bios, start-up and stress test the computer, evaluate stability, and then make adjustments as necessary. The changing Multiplier really throws a wrench in this process.

For those that may not know, what I am referring to is the Bus multiplier that results in the actual core speed. I have overclocked the CPU to 2.7ghz. It idles at 40deg C. When I stress test the build the Multiplier is reduced from x9.0 to x6.0 (2.7ghz -> 1.8ghz) as shown in CPU-Z. This happens when the cores reach about 60deg C (CoreTemp 0.99.4). It will then bump back up to x9.0 when the temp has dropped down to 55deg C or so. How do you stress test a build when the multiplier will just adjust downward to make it stable?

Just to cover my bases, in an attempt to prevent my Multiplier from changing I have made the following changes:
- Selected "Higher Performance" Power plan in Vista's Control Panels
- Disabled Intel Speedstep Tech in BIOS
- Disabled C1E support in BIOS

Some questions:
Is this a safety measure on the mobo/CPU?
Is this a Vista "feature" (will I see this in XP?)?
Can it be disabled?
If it can be, should I disable it to stress test?
is 60-64deg C too hot for this CPU (under full load)? (I have read that 65deg C is hot, but doable)
How do people stress test with a moving multiplier if it can't be disabled?

Thanks for any help that you can provide!
 

caniba

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Yes it is a safety measure.

This is in xp also if I remember correctly but has nothing to do with OC. it is how much resources vista is going to use.

Speedstep and C1E can be disabled and usually is for OC.

60-64 is that under load? if so it is fine.

Are you only using integrated graphics? if so what are you using you pc for that you need to OC? or are you just trying to learn?
 

powertowerpro

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60deg C is under full load ( I am assuming it will get to 64deg if the safety measures are disabled). I am using this machine to take Blu-ray rips (that I own) and encode them using eac3to and Megui. This process will max all 4 cores at 100% for several hours. I want to get a stable build that will not downgrade the multiplier but will also maximize speed. If I have to go back to 2.4ghz I will, but that would be a real shame. Yes, I am using integrated graphics for now...
 

caniba

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60 C under full load is great. I wouldn't go to far with the OC but try to get it around 3Ghz without having to adjust the voltage. that should be easy and keep thing fast without too much temp increase.
 

powertowerpro

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But the problem is that at 60 C the multiplier decreases to x6.0 giving me an affective clockspeed of 1.8ghz. I need to find a way to prevent that. Any ideas?
 

caniba

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I am not familiar with your bios but there must be some other power saving setting in the bios. My gigabyte board has I think 3 things I have to disable to get it to completely disabled.

Google it to see if you can find out if there is any other setting in the bios to disable.
 

htoonthura

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I had that problem before. But, it is at 3.6 G. It was the heat in my case. As soon as it gets hot, even though it is under 70C, it switches back to low multiplier. I can not fix the problem, but i am happy at 3.3 G. You save a little over 1 sec from 3.3 to 3.6 G. The performance gain is not much , but i need to use 1.5 v to get that speed. It is not worth it in my book, so i leave it as it is, Your post kind of reminds me.

 

powertowerpro

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After revisiting the BIOS for the 100th time to see if I missed anything I stumbled upon the "CPU Ratio Setting". It was set to "AUTO". I have changed this to 9.0. I am in the process of stressing the computer to see if it will change back down to 6.0 when it gets too hot. I will post an update with my results. I hope this works.
 

kurtyboh

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i think you have your answer, i was just going to ask if your ratio was at auto... alas too litlle to late. i dont know a lot about oc'ing but i actually recently read about someone having the same problem just a couple of days ago, so i had the
 

kurtyboh

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i think you have your answer, i was just going to ask if your ratio was at auto... alas too litlle to late. i dont know a lot about oc'ing but i actually recently read about someone having the same problem just a couple of days ago, so i had the answer all ready.

kurt

sorry about the double post (kinda) i dropped my keyboard and it sent prematurely
 

powertowerpro

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Well changing the multiplier from auto to 9.0 still doesn't do it, but another setting should, though I am hesitant to change it:

CPU TM Function:
Enables or disables Intel CPU Thermal Monitor function, a CPU overheating protection function. When enabled, the CPU core frequency and voltage is reduced when the CPU over heats.

If I disable this, and the chip overheats, do I risk damaging the CPU or will it simply just shut down? 60 deC just seems like a Low Temp for this to be kicking in.